fix(api): guard shared API client against non-JSON error responses

src/shared/utils/api.ts

@@ -96,10 +96,10 @@ export function getErrorMessage(
 }
 
 async function handleResponse(response: Response) {
-  const data = await response.json();
+  const data = await parseResponseBody(response);
 
   if (!response.ok) {
-    const error: any = new Error(data.error || "An error occurred");
+    const error: any = new Error(getErrorMessage(data, response.status, "An error occurred"));
     error.status = response.status;
     error.data = data;
     throw error;

tests/unit/shared-api-utils.test.ts

@@ -109,3 +109,22 @@ test("shared api utils throw enriched errors for non-OK responses", async () =>
     }
   );
 });
+
+test("shared api utils throw a clean error for non-JSON non-OK responses", async () => {
+  globalThis.fetch = async () =>
+    new Response("Bad Gateway", {
+      status: 502,
+      headers: { "Content-Type": "text/plain" },
+    });
+
+  await assert.rejects(
+    () => get("http://localhost/get"),
+    (error) => {
+      assert.ok(!(error instanceof SyntaxError), "must not be a raw JSON parse SyntaxError");
+      assert.match((error as any).message, /Bad Gateway/);
+      assert.equal((error as any).status, 502);
+      assert.equal((error as any).data, "Bad Gateway");
+      return true;
+    }
+  );
+});